Fastening for pulleys.



A. 0. THORPE. FASTENING FOR PULLEYS.

APPLICATION FILED 111111.12, 1912.

Patented Feb. 17,1914.

V EBTH'UB C. THORPE, 0F

STOCKTON, CALIFORNIA ASSIGNOR OF ONE-HALF TO JAMES BUTLER, OF STOCKTON, CALIFORNIA.

FASTENING FOR PULLEYS.

Specification of Letters'latent.

Patented Feb. 17, 1914.

Application filed August 12, 1912. serial 110.7143

To all whom it may concern:

Be it known hat I, ARTHUR C. Tn'onru, a citizen of the United States, residing at Stockton, in the county of San Joaquin and State offlali forni'a, have invented certain new and useful Improvements in Fastenings for. Pulleys, of which the following is a specification. V

This. invention relates to improvements in deviecsfor fastening pulleys, gear wheels, etc, to shafts, and it is the object of the invention to provide a simple and efiicient fastening of this kind which is devoid of projecting parts, and which does not reuire a keyw'ay inthe shaft or the hub of t e pulley or other part to be fastened thereby maintaining the full strength of the same.

In order that the invention may be better understood, reference is bad to the accompanying drawing forming a part of this specification, in which drawing- Figure 1 is an elevation showing the application of the invention. Fi 2 is a vertical section on the line 2-2 of' ig. 1. Fig. 3 is an end view' and elevation of one of the bushings. Fig. 4. shows similar views of the other bushings Fig. 5 is an end view, and elevation, the'latter being spartly in section, of one of the eccentric bu ings. Fig. 6 is an end view'and elevation of the other eccentric bushing.

Referring specifically to the drawing, A denotes the hub of a pulley, gear wheel, or the like, which is to be made fast on the shaft B. The bore of the hub has a diameter which is greater than that| of the shaft, so that the fastening devices may be applied. Encircling the shaft, within the. bore of the hub, are two eccentric bushings e and which are made of case-hardenedsteel and splitlongitudinally at their thlnnest portions. The two bushings are adapted to be .placed one within the other, with their eccentricities opposite each other, the thinnest portion of one bushing being thus located opposite the thickest portion of the other bushing. The outer surface of the outer bushing e, and the inner surface of the 1nner bushing f, are knurled, as shown in Figs. 5 and 6. These two bushings are adapted to be positioned on that ortion of the shaft which passes'through t e bore of the hub, they being located in the .bore midtivu concentrically and fitting snugly in the bore way between the ends thereof, as shown'in Fig. 2, and when assembled on the shaft,

as stated, they form a perfect circular bushing and locate the pulley so that the shaft extends centrally through the bore of the hub. The bushing e is so dimensioned that it has to be sprung inwardly when positioned within the bore of the hub, in view of which it will beheld in frictional conmet with .the'wallof the bore. The bushing f is sprung on the shaft and is held thereon by frictional contact. The length of the bushings e and j is such that there is s act; on opposite sides thereof, within the ore of the hub, for bushings c and (2, respecsaid bushings encircling the shaft of the hub. The outer ends of the bushings '0 and d are flush with the faces of the hub.

The bushings c and d have the same inside and outside diameters as thebushing formed by the two ecc'entricbushings e and f.

The fastening operates as follows: When the shaft-starts to rotate,-i't carries the bushing f with it owing to the frictional contact between said bushin and the shaft, this being increased by t e knurled inner surface of the bushing. The bushin e is held stationary in the bore of the hub y its frictional contact therewith which is also increased bythe outer knurled surface of said bushing. The thickestportion of the bushmg f is therefore driven in the direction of the thickest portion of the bushing 6. This action tends to wedge the bushings together,

causing the hub to be firmly locked to the shaft. The bushings c and (1 center the shaft in'the hub. bore.- Awedge. action also takes place if the 'power is ap lied to the pulley instead of to the she t, and this wedge act-ion occurs irrespective of the direction in which the shaft or pulley are rotated.

-' The advantage of the herein described fastening will be evident from the foregoing description. No 'ke s, feathers, set screws, etc, are needed, an not weakened by keyways. The motion may be transmitted in either direction. The

fastening can be easily applied-and isdgli e .of persons working close to the pulley. "The void of projecting parts to endanger the device is especially useful for locking parts together in a small space, and also for-parts the shaft and hub areof small diameter, which makes it desirable for use on automobiles, flying machines, motor cycles, etc. a

I claim: 7

1. A. device for'fastening a hub to a shaft comprising eccentric bushings placed one Within the other with their ecoentricities opposite each other and encircling the shaft Within the bore of the hub, the inner bushing being in frictional contact with the shaft, and the outer bushing in frictional contact with the wall of the hub bore, and concentric bushings in the hub bore on opposite sides of the eccentric bushings for centering the shaft therein.

2. A. device for fastening a hub to a shaft comprising a resilient circular bushing fitting around the shaft, said bushing being eccentric and split at its thinnest portion, and a second resilient circular bushing encircling the first mentioned bushing, said second bushing being also eccentric and split at its thinnest portion, and having its outer surface in contact with the Wall of the hub bore, and the eccentricities of said bushings beings diametrically opposite each other.

3. A device for fastening a hub to a shaft comprising a resilient circular bushing fitting around the shaft and having a normal inside diameter which is smaller than the diameter of the shaft, said bushing being eccentric and split at its thinnest portion, and a second resilient circular bushing encircling the first mentioned bushing and having a normal outside diameter which is greater than the diameter of the hub bore, the outer surface of the second mentioned bushing being in contact with the Wall of the hub bore, and said bushing being also eccentric and split at its thinnest portion, the eccentricities of said bushings being diametrically opposite each'other.

In testimony whereof I afix my signature in presence of two Witnesses.

ARTHUR C. THORPE. Witnesses:

ERNEST ARATA, FRANK LAKE. 

